<a href="http://media3.washingtonpost.com/wp-dyn/content/photo/2008/09/09/PH2008090902676.jpg"><img class="alignright" title="Shawne Merriman" src="http://media3.washingtonpost.com/wp-dyn/content/photo/2008/09/09/PH2008090902676.jpg" alt="" width="153" height="219" /></a>SAN DIEGO (AP)-Star outside linebacker Shawne Merriman pulled the plug on his 2008 season on Tuesday when he told the San Diego Chargers he'll have surgery on the two torn ligaments in his left knee.

The loss of Merriman, whose hard hits earned him the nickname "Lights Out," is a big one for a team that has Super Bowl expectations.

Merriman's decision came two days after he barely resembled the player who had an NFL-high 39 1/2 sacks in the past three seasons and played in three straight Pro Bowls.

"Shawne informed me he did not feel right and thought it best to shut it down," Chargers general manager A.J. Smith said in a statement. "The road to winning the AFC West just got more difficult, but not impossible. Nothing is impossible. Shawne is a great player and an inspirational leader. He will be missed. We wish him a successful surgery and a speedy recovery."

Merriman had only two tackles in a shocking 26-24 loss to Carolina at home on Sunday. Even though Merriman appeared to be a non-factor, coach Norv Turner said he thought the linebacker looked "explosive and very physical."

Late in training camp, Merriman said that the posterior cruciate and lateral collateral ligaments in his left knee were torn.

He spent several days getting opinions from four doctors from outside the organization, all of whom recommended he have surgery. But on Aug. 27, he announced that he was going to play, saying, "If you give a football player a decision to play, you know, I'm going to play."

But, he acknowledged, "I'll have the surgery at any point. Nobody knows. I kind of left it on the table when to have it. Not even doctors can tell me that."

Rehab is expected to be six to seven months.

Merriman has said he's had pain in the knee since late in the 2006 season. He also injured the knee during a game at Tennessee on Dec. 9. He sat out the following Sunday, but played in the last three regular-season games and the Chargers' three playoff games, including a loss to New England in the AFC championship game. He also played in the Pro Bowl.

Merriman had offseason arthroscopic surgery to repair torn cartilage in the knee.